Evaluation of Antipsychotic Dose Reduction in Late-Life Schizophrenia

摘要: Importance Patients with late-life schizophrenia (LLS) are highly susceptible to antipsychotic adverse effects. Treatment guidelines endorse lower doses. However, the optimal dose of antipsychotics and associated dopamine D 2/3 receptor (D R) occupancies remain largely unexplored in patients LLS. Objective To evaluate effects reduction on striatal R occupancies, clinical variables, blood pharmacokinetic measures Design, Setting, Participants An open-label, single-arm prospective study a 3- 6-month follow-up period (January 10, 2007, October 21, 2013) was conducted at an academic tertiary care center practice for ambulatory care. included 35 outpatients clinically stable LLS (patients aged ≥50 years receiving olanzapine or risperidone monotherapy same 6 12 months). Follow-up completed 2013, analysis from 22, 2014, February 2, 2015. Interventions Carbon 11–labeled raclopride positron emission tomography, measures, performed before after gradual by up 40% baseline least 3 months reduction. Main Outcomes Measures Striatal antipsychotics, (Positive Negative Syndrome Scale, Brief Psychiatric Rating Targeted Inventory Problems Schizophrenia, Simpson-Angus Barnes Scale Drug-Induced Akathisia, Udvalg Kliniske Undersogelser Side Effect Scale), (prolactin levels). Results Dopamine occupancy entire sample decreased mean (SD) 6.2% (8.2%) following (from 70% [12%] 64% [12%]; P stability 50%. Extrapyramidal symptoms (EPSs) were more likely occur higher than 60%: 90.5% (19 21) participants EPSs 76.9% (10 13) postreduction had 60%. The deterioration (n = 5) those whose condition remained (n = 29) (58% [15%] vs 72% [10%];  = .03). Following reduction, Schizophrenia score increased (  = .046) Positive  = .02),  = .03),  = .02) levels all decreased. Conclusions Relevance Antipsychotic is feasible LLS, decreasing improving illness severity measures. results present suggest therapeutic window (50%-60%) previously reported younger (65%-80%).